Ab Interno Gelatin Stent With Mitomycin C Using Targeted Supra-tenon's Placement

August 4, 2020 updated by: Iqbal Ahmed, Prism Eye Institute
The Xen-45 gelatin microstent is a novel, bleb-forming microinvasive glaucoma surgery (MIGS). Despite demonstrating similar efficacy and safety to trabeculectomy (traditional surgery), the Xen-45 gelatin microstent continues to suffer from occasional surgical failure due to fibrosis of the filtering bleb, and obstruction of the stent. During surgery, placement in a surgery known as supra-tenon's space is believed to maximize aqueous outflow, while preventing obstruction, limiting fibrosis of the bleb, and promoting long-term patency. Despite the theoretical merits, long-term data of outcomes after targeted supra-tenon's placement is needed to fully assess its potential in improving Xen-45 microstent outcomes.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The Xen-45 gelatin microstent (Allergan, Dublin, Ireland) is a novel, bleb-forming microinvasive glaucoma surgery (MIGS). Creation of a filtering bleb through the gel stent and under the conjunctiva lowers intraocular pressure (IOP) by bypassing the natural outflow pathway of aqueous. A recent retrospective cohort study showed comparable safety and risk of failure to trabeculectomy. Amongst the main advantages of this device is the ability to create a bleb without dissecting and disrupting tissue, thus decreasing the amount of wound healing and potentially limiting bleb failure. However, despite demonstrating similar efficacy and safety to trabeculectomy,2 the Xen-45 gelatin microstent continues to suffer from occasional surgical failure due to fibrosis of the filtering bleb, and obstruction of the stent. Although antimetabolites, such as mitomycin C, have decreased reactionary wound healing that can result following surgery, fibrosis may still occur, especially when the components of the Xen-45 gelatin microstent are in close proximity to the fibroblastic structures of tenon's fascia.Tenon's capsule resembles a sponge-like layer with multiple adhesions to the overlying conjunctiva and underlying episclera. Implantation of the XEN within this space creates a higher risk of obstruction and subsequent failure. To ensure the lowest potential for occlusion, bleb scarring, and failure, one must ensure careful placement of the device in the subconjunctival space, avoiding intra-tenon's placement. Placement in the supra-tenon's space is believed to maximize aqueous outflow, while preventing obstruction, limiting fibrosis of the bleb, and promoting long-term patency. Despite the theoretical merits, long-term data of outcomes after targeted supra-tenon's placement is needed to fully assess its potential in improving Xen-45 microstent outcomes.

Study Type

Observational

Enrollment (Actual)

142

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Ontario
      • Oakville, Ontario, Canada, L6H 0J8
        • Prism Eye Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

30 years to 90 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Patients aged 30-90 with primary or pigmentary/pseudoexfolliative open angle, primary closed angle, or combined mechanism glaucoma with IOP of 18-40 mmHg on maximum tolerated medical therapy who received a gelatin stent with MMC at Prism Eye Institute from June 2012 to August 2019.

Description

Inclusion Criteria:

  • Patients aged 30-90 with primary or pigmentary/pseudoexfolliative open angle, primary closed angle, or combined mechanism glaucoma with IOP of 18-40 mmHg on maximum tolerated medical therapy who received a gelatin stent with MMC at Prism Eye Institute from June 2012 to August 2019.

Exclusion Criteria:

  • Other forms of glaucoma
  • Prior incisional glaucoma surgery
  • CPC
  • Prior corneal graft (PKP, DALK, DSAEK, DMEK).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Retrospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Targeted supratenon's placement of XEN 45
Placement of Xen-45 gelatin microstent in the supra-tenon's space to maximize aqueous outflow, while preventing obstruction, limiting fibrosis of the bleb, and promoting long-term patency.
Placement either in the subconjunctival space or supratenon's area
Non-targeted placement of XEN 45
Implantation of the XEN-45 gelatin microstent within the subconjunctival space, avoiding intra-tenon's placement.
Placement either in the subconjunctival space or supratenon's area

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement.
Time Frame: Post op year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤14 (mmHg) on no medications
Post op year 1
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 2.
Time Frame: Post op Year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤14 (mmHg) +/- Medications
Post op Year 1
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 3.
Time Frame: Post op year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤17 (mmHg) on no medications
Post op year 1
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 4.
Time Frame: Post op Year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤17 (mmHg) +/- medication
Post op Year 1
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 5.
Time Frame: Post op Year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤21 (mmHg) on no medications
Post op Year 1
Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 6.
Time Frame: Post op year 1
Mean change in IOP from baseline, IOP thresholds of ≥6 and ≤14 (mmHg) +/- medications
Post op year 1

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With Postoperative Complications Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Non-targeted Placement.
Time Frame: Post op year 1

Presence or absence of the following complications:

i. Starting after POM1: shallow AC w/ iridocorneal touch, any hyphema, corneal edema, wound leak/dehiscience, choroidal effusion, malignant glaucoma, dellen/non-healing epithelial defect, ptosis, diplopia.

ii. At any point: additional glaucoma surgery, loss of light perception vision, vitreous hemorrhage, ≥2mm hyphema, hypotony maculopathy, implant migration/blockage/exposure/extrusion, macular edema, choroidal effusion/hemorrhage requiring drainage, suprachoroidal hemorrhage, retinal detachment, suture abscess/blebitis/endophthalmitis

Post op year 1
Number of Participants With Postoperative Interventions Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Non-targeted Placement.
Time Frame: Post op year 1
Presence or absence of the following management interventions (not considered complications): bleb needling, AC reformation, suture release, digital ocular compression, use of glaucoma medications, or laser/tpa to blocked ostomy or lumen.
Post op year 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Iqbal Ike Ahmed, MD, Prism Eye Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 25, 2019

Primary Completion (Actual)

April 20, 2020

Study Completion (Actual)

April 20, 2020

Study Registration Dates

First Submitted

June 23, 2020

First Submitted That Met QC Criteria

June 26, 2020

First Posted (Actual)

July 1, 2020

Study Record Updates

Last Update Posted (Actual)

August 14, 2020

Last Update Submitted That Met QC Criteria

August 4, 2020

Last Verified

August 1, 2020

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 955

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Glaucoma

Clinical Trials on XEN-45 gelatin microstent

3
Subscribe